Agricultural Science Commons^™

Genetic Resources For The Improvement Of Switchgrass (Panicum Virgatum L.) For Biomass And Forage, Gautam Sarath, Nathan A. Palmer, Aaron J. Saathoff, Robert B. Mitchell, Serge Edme, Erin D. Scully, Scott E. Sattler

IGC Proceedings (1977-2023)

Switchgrass (Panicum virgatum L.) is an important forage and biomass species for many parts of the USA. Switchgrass can be of several ploidies. Octoploid cultivars are most often used in forage and conservation settings, while the tetraploid cultivars are mostly targeted for bioenergy end-uses, due to their higher biomass yields. Switchgrass populations also occur as upland and lowland ecotypes, and constitute different heterotic groups. Switchgrass is mostly an obligate outcrosser resulting in substantial genotypic and phenotypic variation within populations. In the last ~15 years, significant resources have been dedicated to both breeding and understanding the genomic makeup of this …

Genetic Improvement And Conservation Of Range And Forage Species Of Arid Region Of Rajasthan State Of India: Achievements And Challenges, Surendra Singh Shekhawat

IGC Proceedings (1977-2023)

Forage crops and grasses are important in arid region of Rajasthan state of India because most of the area is rainfed. Main occupation of the farmers in the area is animal husbandry. Important green fodder crops of this region are, viz. pearl millet, cowpea, cluster bean and sorghum in Kharif season and oats, lucerne and barley (dual purpose) during Rabi season. Three perennial fodder grasses, viz. Lasiurus sindicus, Cenchrus ciliaris and Cenchrus setigerus are important in the region. Guinea grass and bajra x napier hybrid can also be cultivated where sufficient water is available throughout the year from canal …

Morphological Variability Potential Of Cenchrus Ciliaris L. Ecotypes On Their Phytochemical Substances And Antibacterial Activities, Dorai Pandian Kannan, S. Bagam Priyal

IGC Proceedings (1977-2023)

Ecotypes are population of same species with different races, which is adapted to local environment Different ecotypes of a particular species may differ in their edaphic, biotic or microclimatic requirements (Linhart and Grant, 1996; Eppela et al., 2013) and such adaptation either become irreversible or genetically fixed variations. Cenchrus ciliaris L. (Tam: kollukottaipul, Eng. buffel grass, Sans: anjan grass) is a grass belonging to the family Poaceae and ephemeral in nature. In this species, habitat plays a significant role in the formation of ecotypes and several ecotypes are found in Cenchrus ciliaris L. including with varying …

In Situ Plant Uptake Of Excess Nutrients And Consequential Alteration Of Rhizosphere Dynamics, Srusti Maddala

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The use of phytoremediation in ecological remediation projects has numerous benefits including soil stabilization and nutrient uptake. Recently, microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has been recognized as a candidate for monitoring chemical changes in the rhizosphere. The real-time, in situ data it provides about nutrient diffusion may improve the management and success of restoration projects. Therefore, the objective of this study was to employ the technique of microdialysis in the novel application of quantifying the diffusive flux of inorganic nitrogen compounds in the rhizosphere of native plants of Arkansas. The microdialysis technique was first optimized …

Optimal Calving Time For Beef Cows In Southwest Missouri, Briana Rose Verploeg

Graduate Theses/Dissertations

The purpose of this study is to determine if a optimal time of year exists for beef producers to have cows give birth in southwest Missouri for maximal net returns from calf sales and increased cow reproductive performance. To make this determination, data were collected which included year-round forage nutritive value, calf pre-weaning growth, cow energy efficiency and reproductive performance, and income and cost values. Cow and calf field data were gathered for the 2014-2018 production years at Missouri State University’s Leo Journagan Ranch. Monthly forage samples were collected from study cow pastures from 2016 through 2018. Calf, cull cow, …

Use Of Acetolactate Synthase-Inhibiting Herbicides In Inzen Grain Sorghum (Sorghum Bicolor L. Moench Ssp. Bicolor), Hunter Bowman

Graduate Theses and Dissertations

Grain sorghum is typically grown as a rotational crop in Arkansas because of its many benefits, one being the effective control of Palmer amaranth through the use of atrazine. However, limited options exist for postemergence (POST) control of weedy grasses within the crop. Inzen™ grain sorghum is the result of a nicosulfuron resistant weedy sorghum biotype cross-bred with a commercial line of grain sorghum. Inzen™ allows for safe use of over-the-top applications of nicosulfuron within the crop. Nicosulfuron is an acetolactate synthase (ALS)-inhibiting herbicide, which has historically been used in corn for control of weedy grasses. Experiments were conducted in …

Midseason Nitrogen Sufficiency Guidelines For Corn Production In Arkansas Based On Tissue Analysis And Remote Sensing, Caio Luiz Dos Santos

Graduate Theses and Dissertations

There are a lack of tools to assess midseason nitrogen (N) status in corn (Zea mays L.) production systems and identify the need for additional N fertilization. This study was conducted to determine the ability of leaf N concentration (LN) and the Dark Green Color Index (DGCI) at the 10th collared leaf stage (V10), the 12th collared leaf stage (V12), and tasseling (VT) to predict if midseason N is required to maximize corn grain yield. From 2017 to 2019, eight field studies with 11 N treatments ranging from 0 to 258 kg N ha-1 were conducted on silt loam soils …

Elucidating Basis Of Rice Discoloration And Developing Prevention Strategies, Zeinab Mohammadi Shad

Graduate Theses and Dissertations

Economically, discolored rice kernels have less market value, which can seriously impact farm net profit. The reasons for rice discoloration during storage have not been studied extensively and many questions remain. Therefore, the primary goal of this study was to improve understanding of the role and contributions of storage practices on rice quality degradation and discoloration. In this study, three rice cultivars including XL753 (hybrid), Roy J (pureline), and Titan were assessed for changes in quality and microbial kinetics. The rice samples at a high moisture content (MC) of 21% w.b. and a low MC of 16% were stored at …

Resilience To Large, “Catastrophic” Wildfires In North America's Grassland Biome, Victoria M. Donovan, Dirac Twidwell, Daniel R. Uden, Tsegaye Tadesse, Brian D. Wardlow, Christine H. Bielski, Matthew O. Jones, Brady W. Allred, David E. Naugle, Craig R. Allen

Department of Agronomy and Horticulture: Faculty Publications

Wildfires are ecosystem‐level drivers of structure and function in many vegetated biomes. While numerous studies have emphasized the benefits of fire to ecosystems, large wildfires have also been associated with the loss of ecosystem services and shifts in vegetation abundance. The size and number of wildfires are increasing across a number of regions, and yet the outcomes of large wildfire on vegetation at large‐scales are still largely unknown. We introduce an exhaustive analysis of wildfire‐scale vegetation response to large wildfires across North America's grassland biome. We use 18 years of a newly released vegetation data set combined with 1,390 geospatial …

Techniques To Enhance The Attributes Of Wines Produced From Grapes Grown In Arkansas, Sarah Mayfield

Graduate Theses and Dissertations

Grapevines (Vitis spp.) are one of the most widely-planted horticultural crops, and the United States plays a major role in grape and wine production. Arkansas has a long history of grape and wine production with grapes grown in Arkansas including mostly native species, such as muscadines, and hybrids (crosses of Vitis spp.), such as Chambourcin. In addition, the University of Arkansas System Division of Agriculture (UA System) grape breeding program has cultivars and selections that have shown potential for wine production. The objectives of this research were to: evaluate effects of specific inactivated yeast application to Chambourcin grapevines on attributes …

Control Of Volunteer Corn In Enlist Corn And Economics Of Herbicide Programs For Weed Control In Conventional And Multiple Herbicide-Resistant Soybean Across Nebraska, Adam Michael Striegel

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

With commercialization of multiple herbicide-resistant corn and soybean cultivars, producers have new management options for controlling herbicide-resistant weeds and volunteer corn. Corn-on-corn production systems are common in irrigated fields in southcentral Nebraska which can create issues with volunteer corn management in corn fields. Enlist corn contains a new multiple herbicide-resistant trait providing resistance to 2,4-D choline, glyphosate, and the aryloxyphenoxypropionate (FOPs). Field experiments were conducted in 2018 and 2019 at South Central Agricultural Laboratory near Clay Center, Nebraska with the objective to evaluate ACCase-inhibiting herbicides and herbicide application timing on volunteer corn control, Enlist corn injury, and yield. Glyphosate/glufosinate-resistant corn …

Buffalograss Diversity Assessment, Jesse Collin Marshall

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Buffalograss [Buchloë dactylodes (Nutt.) Engelm. syn. Bouteloua dactyloides (Nutt.) Columbus] is a low input alternative turfgrass for the Great Plains region. Buffalograss is a dioecious stoloniferous warm season grass with wide variation of valuable traits and is well adapted for use in minimal maintenance landscapes. The obligate outcrossing nature of the species and wide variation of potentially valuable traits make buffalograss a prime candidate for cultivar improvement and genetic study. Limited information is available regarding buffalograss genetics. In effort to expand genetic resources around buffalograss, we developed buffalograss derived simple sequence repeat markers from previously available transcriptomes of buffalograss …

Impact Of Agricultural Land Use On Stream Nitrate, Phosphorus, And Sediment Concentrations At The Watershed And Field Scale, Brittany A. Kirsch

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Water quality is directly impacted by the landscape through which it travels. As such, land use, including summer annual and winter annual/perennial agriculture, has dramatic influence on the water quality of downstream aquatic and terrestrial ecosystems. I examined the impact of agricultural land use on water quality through two projects, one at a watershed scale and one at a field scale. In my first project, I investigated the impact of agricultural land use and climate on water quality in 13 HUC10 watersheds across Nebraska using public data from US Geological Survey (USGS), US Department of Agriculture National Agricultural Statistics Service …

Determination Of Critical Y-Leaf Potassium Concentrations Across Reproductive Growth Stages For Direct-Seeded Delay-Flooded Rice, Chandler Edwin Gruener

Graduate Theses and Dissertations

Rice (Oryza sativa L.) grain yield can be limited by potassium (K) deficiency on soils low in exchangeable K. Visually diagnosing K deficiency during early reproductive growth is not easily done and the interpretation of traditional tissue analysis is limited to select growth-stages. Our primary focus was to define continuous critical Y-leaf-K concentrations during reproductive growth for the production of maximal grain yield. A secondary objective was to examine Y-leaf sap-K concentration, measured using a handheld device, as a rapid in-field method of monitoring rice plant K nutrition. The Y-leaf is defined as the uppermost fully extended leaf with a …

An Evaluation Of Biopesticide Combinations On Yield Performance And Disease/Arthropod Control Of Strawberries Grown In High Tunnel Plasticulture Production Systems In Arkansas., Karlee B. Pruitt

Graduate Theses and Dissertations

This two-year study investigated combinations of biopesticides to determine impacts on strawberry fruit marketable fruit yields, and effectiveness in controlling strawberry pests in a high tunnel production system at the University of Arkansas, Division of Agriculture Research and Extension Center in Fayetteville, Arkansas. Two strawberry cultivars Fragaria × ananassa (Duch.), Camino Real and Sweet Sensation were grown in a high tunnel from early-October to mid-May for two consecutive growing seasons, (2017-18 and 2018-19) with six treatment combinations of biopesticides including an untreated (water) control, nutrient spray and selected biological based fungicides and insecticides, arranged into a split-plot randomized block design. …

Synthesis And Characterization Of Synthetic Urban Melt Glass, Rebecca Kristien Lowe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Melt glass formed from the explosion of a nuclear device is a unique post-detonation material that can aid in the ensuing forensics investigation. Trapped in the melt glass are chemical and isotopic signatures that can provide diagnostic and source information about the weapon by comparison with documentation of previous detonations. A nuclear terrorist attack would likely take place in an urban environment and as such, the melt glass formed would consist of a complex matrix including urban materials like cement and glass, activation products from the large neutron flux that will be seen, and fission products from the detonation. The …

The Economics Of On-Farm Rice Drying In Arkansas, Clayton Parker

Agricultural Economics and Agribusiness Undergraduate Honors Theses

Globally, rice producers are faced with the temporal problem of deciding the optimal time to being rice harvest. When harvested, paddy rice is typically at a moisture content (HMC) between 15 and 22%. Upon delivery, the rice is subsequently dried by the mill to a moisture content (MC) of 12.5%. Riceland Foods Inc., the largest miller of rice in the world, uses a stair-step pricing model to charge farmers to dry in price/unit as the MC of grain decreases from a range of +22% to 13.5%. This study estimates an alternative linear relationship in the stair-step model to determine MC …

The Australian Pastures Genebank, Steve Hughes

IGC Proceedings (1977-2023)

Australian grazing enterprises, including all food and fibre productions, as well as crop rotation, are worth $42 billion per annum to the Australian economy, employing around 693,000 Australian workers. Australia has been a major beneficiary from the introduction and utilization of genetic resources in pasture and forages. Assured access to plant genetic diversity underpins Australia’s ability to maintain agricultural productivity in the face of environmental and economic challenges.

Australia is custodian of potentially the world’s largest and globally significant collection of pasture and forage genetic resources. Much of this is unique and held in state-based collections and represents an invaluable …

The Landscape As A Unit For Rangeland Inventory In Arid And Semi-Arid Regions Of Iran (Case Studies: Touran Biosphere Reserve And Behkadaye Rajinia Development Project), Mansour Mesdaghi

IGC Proceedings (1977-2023)

Severe land fragmentation, degradation, and pollution problems will force us to think about a rural community and research group in Iran to combine our experiences and skills to deal with the challenges of improving land use sustainability (Bosch at el.1995; Mesdaghi, 1993). Planning rangeland inventory requiring recognition of the ecological processes operating at different scales and their particular characteristics (Friedel and Laycock, 1995).

In ancient countries like Persia (Iran), past land use suggests that rangelands exploitation by local herders was co-adapted with natural environments (Nyerges, 1980; Mesdaghi, 1993). Iranian rangelands, however, were nationalized through the land reforming and the …

Livestock Grazing In India: Policy Issues, M. M. Roy

IGC Proceedings (1977-2023)

The grazing/range lands have been very important in India since ancient times when cattle breeding and milk production was regarded as the second most important profession, next only to agriculture. However, during last five decades increasing domestic animal population has placed enormous grazing pressure on such lands, leading to grassland deterioration and desertification especially in arid and semiarid regions (GOI, 2007; Kala, 2009).

Still, grazing based livestock play an important role in rural economy of the as well over 50 per cent of them depend on grazing (of varying degrees) in forests, community lands and other lands in many parts …